Composite Films Of Conducting Polymers And Their Electrochemical Devices

Composite films of conducting polymers (CP) usually have excellentproperties and multiple functions. Thus, they have potential applications infabricating various electrochemical devices. In this dissertation, three types ofpolypyrrole (PPy) composite films were synthesized through differentstrategies. The conductivity, surface adhesive or mechanical property ofpolypyrrole film has been greatly improved. The electrochemical actuators orsupercapacitors based on these composite films exhibit improved propertiesand functions. The main contents and results are summarized as follows.A PPy/Au bi-layer composite film was fabricated by electrochemicaldeposition and its surface was modified with a bio-adhesive polymer,polydopamine. The actuator based on the composite film exhibited highperformances of actuation in physiological media. Furthermore, the surface ofthe actuator is sticky in water, and thus can seize bacteria from their aqueoussolutions. Actuation greatly increased the efficiency of adhering bacteria onthe actuator surface, and this technique provides a cheap and convenientapproach for accumulating bacteria from physiological media.A tri-layer composite film was fabricated by the electrodeposition of PPyonto a sulfonated graphene (SG)/reduced graphene oxide (RGO) bi-layer filmwith sandwich structure. During electrical actuation, PPy and RGO were actedas actuation and conductive inert layers, respectively. The SG layer was usedto enhance the interfacial interactions. The tri-layer actuator exhibited highand stable actuating performance for over1,000actuation cycles, and thelifetime of the actuator was tested to be about5,000cycles. The bending angleof the actuator is larger than360oand its movement rate was higher than150os1under a driving potential of1.0V versus saturated calomel electrode(SCE). Furthermore, the low weight density of graphene based supportinglayer greatly lowered the energy or charge consuming of the actuator duringelectrochemical actuation. Composite films of sulfonated graphene (SG) and polypyrrole (PPy) wereelectrochemically deposited from the aqueous solutions containing pyrrolemonomer, SG sheets and dodecylbenzene sulfonic acid (DBSA). During theprocess of electrochemical polymerization, negatively charged SG sheetsacted as a dopant of PPy. Thus, they were uniformly dispersed in the PPymatrices of resulting composites. The introduction of SG sheets improved theconductivity and electrochemical properties of PPy films. The supercapacitorbased on the composite films containing about46%(by weight) SG showed ahigh specific capacitance of285F g1at a discharge rate of0.5A g1. Theyalso exhibited greatly improved electrochemical stability and rateperformances.